1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
J.T. Fasullo and K.E. TrenberthNCAR
Global Warming Caused By Increased Absorbed Solar Radiation
1Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Simulated Global Warming Caused By Increased Absorbed Solar Radiation
J.T. Fasullo and K.E. TrenberthNCAR
1Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Outline
2Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Outline• Science Questions
2Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Outline• Science Questions
• Background / Expectations
2Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Outline• Science Questions
• Background / Expectations
• Evolution of Simulated Global Budgets
2Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Outline
• Regional and Latitudinal Structure
• Science Questions
• Background / Expectations
• Evolution of Simulated Global Budgets
2Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Outline
• Regional and Latitudinal Structure
• Science Questions
• Background / Expectations
• Evolution of Simulated Global Budgets
• Processes?
2Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Outline
• Regional and Latitudinal Structure
• Science Questions
• Background / Expectations
• Evolution of Simulated Global Budgets
• Processes?
• Implications
2Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Our Questions: What Drives Simulated Climate Change?
3Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Our Questions: What Drives Simulated Climate Change?
Set 1: Immediate / Specific
3Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Our Questions: What Drives Simulated Climate Change?
• What is the basic character of the planetary imbalance?Set 1: Immediate / Specific
3Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Our Questions: What Drives Simulated Climate Change?
• What is the basic character of the planetary imbalance?What are its spectral and regional characteristics? What is its temporal evolution?
Set 1: Immediate / Specific
3Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Our Questions: What Drives Simulated Climate Change?
• What processes govern the energy budget?
• What is the basic character of the planetary imbalance?What are its spectral and regional characteristics? What is its temporal evolution?
Set 1: Immediate / Specific
3Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Our Questions: What Drives Simulated Climate Change?
• What processes govern the energy budget?
• What is the basic character of the planetary imbalance?What are its spectral and regional characteristics? What is its temporal evolution?
Set 1: Immediate / Specific
Set 2: General
3Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Our Questions: What Drives Simulated Climate Change?
• What processes govern the energy budget?
• What is the basic character of the planetary imbalance?What are its spectral and regional characteristics? What is its temporal evolution?
• Why has the inter-model spread of simulated climate sensitivity remained so large in successive model generations?
Set 1: Immediate / Specific
Set 2: General
3Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Our Questions: What Drives Simulated Climate Change?
• What processes govern the energy budget?
• What is the basic character of the planetary imbalance?What are its spectral and regional characteristics? What is its temporal evolution?
• Why has the inter-model spread of simulated climate sensitivity remained so large in successive model generations?
• Do meaningful observational proxies of sensitivity exist?
Set 1: Immediate / Specific
Set 2: General
3Thursday, April 30, 2009
Our expected view of Climate Change
War
min
g
Moi
sten
ing
?
? ?SW LW
Other expectations
4Thursday, April 30, 2009
Our expected view of Climate Change
War
min
g
Moi
sten
ing
?
? ?SW LW
Other expectations
1) relative humidity is constant
4Thursday, April 30, 2009
Our expected view of Climate Change
War
min
g
Moi
sten
ing
?
? ?SW LW
Other expectations
1) relative humidity is constant
2) low clouds dominate cloud feedbacks and differentiate
model sensitivity
4Thursday, April 30, 2009
Our expected view of Climate Change
War
min
g
Moi
sten
ing
?
? ?SW LW
Other expectations
3) greatest warming is at high latitudes
1) relative humidity is constant
2) low clouds dominate cloud feedbacks and differentiate
model sensitivity
4Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
The CMIP3 Archive
5Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
The CMIP3 Archive• 24 coupled simulations spanning the 20th and 21st
centuries from 18 modeling centers
• SRES-A1b
5Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
The CMIP3 Archive• 24 coupled simulations spanning the 20th and 21st
centuries from 18 modeling centers
• SRES-A1b
• Excluded simulations that include flux corrections, large errors in the atm budget or in the archive.
5Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
The CMIP3 Archive• 24 coupled simulations spanning the 20th and 21st
centuries from 18 modeling centers
• SRES-A1b
• Excluded simulations that include flux corrections, large errors in the atm budget or in the archive.
• This leaves us with 13 simulations.
5Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
The Planetary Imbalance
• Net planetary imbalance increases through the 21st century
6Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
The Planetary Imbalance
• Net planetary imbalance increases through the 21st century
7Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
The Planetary Imbalance
• Net planetary imbalance increases through the 21st century
• Clouds lessen the imbalance. (Mean State - Not feedback!)
7Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
The Planetary Imbalance
• Current imbalance is ~0.8 W m-2
• Late 21st century imbalance is ~1-2 W m-2 and begins to decline
8Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
The Planetary Imbalance
• In current climate OLR’ heat the planet. Aerosols cool it.
9Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
The Planetary Imbalance
• In current climate OLR’ heat the planet. Aerosols cool it.
9Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
The Planetary Imbalance
• Feedbacks in ASR drive the imbalance after 2100 and to equil.
• In current climate OLR’ heat the planet. Aerosols cool it.
9Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
What regions are processes are suggested?
10Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
What regions are processes are suggested?
lapse rate feedback?OLR
water vapor feedback?cloud feedback?
10Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
What regions are processes are suggested?
lapse rate feedback?OLR
water vapor feedback?cloud feedback?
ice albedo feedback?ASR
cloud feedback?land snow feedback?
aerosol forcing?
10Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Regional Structure
11Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Regional Structure
11Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Lat/Time Structure of the Imbalance
• Planetary Imbalance >0, 50N-50S, ice-albedo feedback suggested to be weak
12Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Lat/Time Structure of OLR Anomalies
• OLR anomalies > 0 except for deep tropics and southern oceans
13Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Lat/Time Structure of ASR Anomalies
• ASR increases at all latitudes except 45-65S
14Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Lat/Time Structure of Cloud %
• In regions of RT and ASR increase, cloud change is < 0
15Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Lat/Time Structure of Cloud %
• Loss of mid-level clouds is more intense and extensive than for other types.
16Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Lat/Time Structure of Cloud %
• Loss of mid-level clouds is more intense and extensive than for other types.
16Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Lat/Time Structure of Cloud %
• Loss of mid-level clouds is more intense and extensive than for other types.
16Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Relationship to Sensitivity
17Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Relationship to Sensitivity
18Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Role of Model Resolution
19Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Role of Model Resolution
19Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Role of Model Resolution
19Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Conclusions: Set 1
20Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Conclusions: Set 1
• Spectral contributions to the planetary imbalance evolve.
• LW 20th and early 21st centuries
• SW mid- to late-21st century and beyond
• (LW is a net negative feedback)
20Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Conclusions: Set 1
• Spectral contributions to the planetary imbalance evolve.
• LW 20th and early 21st centuries
• SW mid- to late-21st century and beyond
• (LW is a net negative feedback)
• Cloud loss largely drives the reduction in Albedo
20Thursday, April 30, 2009
1. Background 2. Timeseries 3. 4D Imbalance 4.Hovmöllers 5. Sensitivity 6. Model Resolution 7. End CERES Science Team Meeting, Apr 2009
Conclusions: Set 2
• Large implications for efforts to gauge sensitivity based on present-day variability. Models suggest that current warming is NOT driven or distinguished by the processes that primarily determine S.
• Cloud loss sensitivity largely determines S
21Thursday, April 30, 2009